Sportsman 500 overheating
My 2000 Sportsman 500 keeps getting hot and puking out coolant. I know the radiator is clean, both sensors are good, and the fan is working. It takes quite a while to get hot, but after it does it begins to hiss and spit fluid out of the reservoir vent hole. It'll run a long time like that, slowly spitting out coolant and the fan seems to cycle on and off normally, but eventually it spits out enough fluid for the hot light to come on and I have to shut it down.
So that leaves me with 3 possibilities......thermostat is stuck (I have a new one on order that should be here this evening), the water pump is shot, or there is air in the cooling system.
Unfortunately, I don't have an owner's manual (yes, I know that I need one), but I'm very familiar with Polaris machines (mainly RZR's and Rangers) and know what a pain they can be to get all of the air bled out of the system. Is the Sportsman the same? Where is the bleeder screw?
Is there a test I can do (other than disconnecting a water pump hose) to see if the water pump is working?
Where is the thermostat located on this machine? I assume that it's on or near the head and think I'll probably recognize it when I start searching, but it was dark last night when I limped it home and I had to work today, so I haven't had a chance to look yet.
I looked all over YouTube but can't find a video that shows/explains any of those questions. They only talk about the potential causes (which I already knew).